Aspects of the present invention relate to a secondary battery.
Secondary batteries include an electrode assembly formed by sequentially stacking a positive electrode plate, a negative electrode plate and a separator and winding the same in one direction, a can housing the cylindrical electrode assembly, and a cap plate sealing an open portion of the prismatic can to thereby form a bare cell. The secondary battery generally includes an electrode terminal insulated from the cap plate and serving one of electrodes in the secondary battery. The cap plate and the can may serve the other electrode in the secondary battery.
In the secondary battery, the electrode assembly is wound and then housed into a can in a planar state. When the electrode assembly swells during repeated charge/discharge operations, both of the planar side surfaces of the electrode assembly also swell.
Accordingly, the swelling of the electrode assembly may result in swelling of the can, specifically both side surfaces which have relatively large areas.
In order to achieve the above and other aspects of the present invention, one embodiment of the present invention provides a secondary battery including a plurality of cylindrical electrode assemblies, which is capable of preventing a prismatic can from swelling.
At least one of the above and other features and advantages may be realized by providing a secondary battery including a plurality of cylindrical electrode assemblies wound in a jelly-roll configuration, each having a positive electrode tab connected to a positive electrode plate, and a negative electrode tab connected to a negative electrode plate, a prismatic can housing the plurality of cylindrical electrode assemblies, center pins inserted into the plurality of cylindrical electrode assemblies and coupled to the bottom of the can, and a cap assembly sealing the prismatic can.
In the secondary battery according to the embodiments, swelling of the prismatic can may be prevented by forming a plurality of cylindrical electrode assemblies wound in a jelly-roll configuration and housed in the prismatic can.